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Nexon Gasoline – EMS ECU Bosch
DTC Troubleshooting Manual
Version: 0.1
Date: 26-08-2017
Prepared By: Sunu S Babu/Yogesh Jadhav
Checked By: Yeshwant Jadhav
Approved By: Satish Kumar
Document Part No: 2921 02 224 A1736
Page: 93 of 1203
Copyright ©
TATA MOTORS Ltd.
This document must not be used in any way, such as copying and redistributing to third parties, without the consent of author.
Trouble Shooting:-
Step Checks
IF YES
IF NO
1.
Is there any rust/oxidization observed on Sensor Terminals Clean the Rust or
repair or replace
Go to Step 2
2.
Is there wiring harness electrical continuity between
ECUpins 239, 206, 202 & Lambda Sensor connector pins
2, 3, 4? Also Check continuity between the Main Relay
supply and the Lambda Sensor Connector pin 1.
Go to Step 3
Establish continuity
by rectifying
harness
connections as per
the Circuit
schematic
3. Are there any pins damaged at Sensor/EMS ECU
Connector
Replace the
connector or wiring
harness
Go to step 4
4
Are there any pins backed out from the Sensor/EMS ECU
Connector
Rectify/Replace
Connectors
Go to Step 5
5
Is Sensor getting GND at pin 204?
Repair the harness
as per the schematic Go to Step 6
6
Is Sensor Signal Pin 202 or heater pin 239, Short Circuited
to Battery/Ground or Open?
Repair the harness
as per the schematic Go to Step 7
7
Is Sensor physically Damaged
Replace Sensor
Go to Step 8
8
Is Sensor poisoned or contaminated
Replace Sensor
Go to Step 9
9. Is there any leakage in Exhaust system
Repair the
damage/leaks
Go to step 10
10 Fault Still Persists?
Replace Sensor and
then Fault still
persists then
Replace EMS ECU
Follow the steps
again for
reconfirmation
DTC’s confirmation:-
After rectification, ensure the following points by referring engine parameters using TML diagnostic tool before
handing over to customer.
1. Fuel system status
2. Engine load
3. Engine coolant temperature.
4. Long term fuel trim.
5. MAP Sensor.
6. Engine Speed.
7. Vehicle Speed.
8. Spark timing.
9. Absolute throttle position.
10. Distance Travelled after MIL ON.
11. Distance travelled since fault memory last cleared.
12. Battery voltage.
Recheck the fault using TML Diagnostic tool, Fault shall not appear.